Hydraulic pressure amplifying apparatus

ABSTRACT

A HIGH-PRESSURE HYDRAULIC PUMP IS CONNECTED WITH A TWO-STAGE PRESSURE AMPLIFIER BY A THREE-WAY DISTRIBUTOR VALVE WHICH CAN SEAL THE PUMP OUTLET FROM THE AMPLIFIER IN A FIRST POSITION AND THEN DISCHARGES PRESSURIZED LIQUID TO A FIRST CONSUMER AT A FIRST PRESSURE. IN A SECOND POSITION OF THE DISTRIBUTOR VALVE, THE ENTIRE OUTPUT OF THE PUMP IS ADMITTED TO THE AMPLIFIER WHICH CAN DISCHARGE FLUID AT A   HIGHER OR LOWER SECOND PRESSURE WHICH EXCEEDS THE FIRST PRESSURE. IN A THIRD POSITION OF THE DISTRIBUTOR VALVE, THE LATTER ADMITS SOME LIQUID TO THE AMPLIFIER AND DISCHARGES THE REMAINING LIQUID AT FIRST PRESSURE.

Jan. 19, 1971 P. HAMMELMANN ETAL 3,556,688

HYDRAULIC PRESSURE AMPLIFYING APPARATUS 3 Sheets-Sheet 1 Filed Jan. 2. 1969 Inventor:

Paul Hamme/mann Ulrich 'Barnowski their Attorney v P. HAMMELMANN ET-AL HYDRAULIC PRESSURE 'AMPLIFYING APPARATUS Jan. 19, 1971 3 Sheets-Sheet z Filed Jan. 2. 1969 v NEW m 8 2 Q 8 Ill lll II x Q? w 7/ .l. v W W I 1112. I M u w m3 v3 mo N8 ma J2 m3 m3 i a 3 Hfi a: IL 1L 2L IL 5 1 1 a 5 u their Attorney 3 Sheets-Sheet a 1971 P. HAMMELMANN AL HYDRAULIC PRESSURE AMPLIEYING APPARATUS Filed Jan. 2, 1969 Paul Hammelmam Ulrich Barno wski their Attorney r w MM x m IIIV J S we 8 8 SS 3 v Q: m b 1 r/Wfl /7 w. b 3nd A:

a 5 n /Q: m" 3 I 12 M n8 mg m m \K N u V L United States Patent O 3,556,688 HYDRAULIC PRESSURE AMPLIFYING APPARATUS Paul Hammelmann and Ulrich Barnowski, Oelde, Westphalia, Germany, assignors to Paul Hammelmann Maschinenfabrik, Oelde, Westphalia, Germany Filed Jan. 2, 1969, Ser. No. 788,420

Claims priority, application Germany, Jan. 2, 1968,

1,653,474 Int. Cl. F04b 17/00 US. Cl. 417-397 7 Claims ABSTRACT OF THE DISCLOSURE A high-pressure hydraulic pump is connected with a two-stage pressure amplifier by a three-way distributor valve which can seal the pump outlet from the amplifier in a first position and then discharges pressurized liquid to a first consumer at a first pressure. In a second position of the distributor valve, the entire output of the pump is admitted to the amplifier which can discharge fluid at a higher or lower second pressure which exceeds the first pressure. In a third position of the distributor valve, the latter admits some liquid to the amplifier and discharges the remaining liquid at first pressure.

BACKGROUND OF THE INVENTION The present invention relates to improvements in hydraulic pressure amplifying apparatus which can supply highly pressurized liquids at several pressures. Such apparatus are often utilized for cleaning of surfaces on submerged bodies with jets of water or other suitable liquid.

Presently known hydraulic apparatus for such purposes are normally equipped with a so-called triplex drive having sets of plungers and sealing elements of different diameters. The stroke and the strength of motion transmitting rods are constant. The output decreases with decreasing diameters of plungers but the pressure increases accordingly. A drawback of such apparatus is that their conversion for operation at different pressures involves alterations of valve systems and utilization of several sets of conduits, guns, nozzles, hoses and other accessories.

It is also known to vary the pressure of fluid by regulating the speed of the drive for the pump. This is impractical for many purposes because the stresses to which the driving parts are subjected vary; i.e., such parts are quite bulky because they must be dimensioned to take up and to resist maximum stresses.

Another drawback of known hydraulic pressure amplifying apparatus is that the persons in charge are likely to sustain serious injuries on faulty operation of the controls or when a hose or another part which is designed to stand relatively low pressures is employed while the apparatus discharges liquid at elevated pressure. Accidents in manipulation of conventional apparatus are frequent and often of very serious nature because the pressure of discharged liquid is in the range of 1001,000 atmospheres superatmospheric pressure. At a pressure in excess of 200 atmospheres, the speed of the jet of discharged liquid is such that a careless operator can sustain severe injuries.

The manufacturers of auxiliary equipment for highpressure hydraulic apparatus can furnish valves, hoses, conduits and other accessories which can readily stand the aforementioned range of elevated pressures. For example hoses with an internal diameter of up to 10 millimeters are available for transport of liquids at a pressure of up to and in excess of 1,000 atmospheres. However, such hoses can only stand a pressure of 1,000 atmospheres if the liquid is transported without appreciable fluctuations in 3,556,688 Patented Jan. 19, 1971 "ice pressure. Hoses with a diameter of 25-30 millimeters are available for transport of liquids at a pressure of up to 200 atmospheres. However, such large-diameter hoses are unsafe when the pressure of conveyed liquid rises beyond 200 atmospheres and are outright dangerous when the pressure rises appreciably above such maximum permissible value. This explains some of risks involved in handling of aforedescribed conventional hydraulic pressure amplifying apparatus wherein a different set of auxiliary parts should and must be used when the liquid is being conveyed at widely different pressures. Repeated exchange of auxiliary equipment consumes much time and is cumbersome to operators, especially if the apparatus is intended to supply highly pressurized liquid to guns which are manipulated by divers for cleaning of surfaces on ships hulls, columns which are mounted in the bottoms of rivers or in other bodies of water, and analogous sub merged or partly submerged structures. Furthermore, several sets of auxiliary equipment contribute to the initial and maintenance cost as well as to the bulk of such apparatus. Moreover, the conversion of conventional apparatus for operation at different pressures must be carried out by skilled operators and invariably results in lengthy interruptions. Still further, the guns or analogous liquid discharging devices which receive pressurized liquid from the outlets of conventional apparatus must be provided with specially designed safety devices to insure instantaneous termination of liquid discharge. Such guns are normally provided with hydrodynamic auxiliary controls which are effective at pressures in the range of several hundred atmospheres. Sudden termination of liquid discharge invariably produces pronounced pressure impulses which subject the hoses and other auxiliary equipment to excessive stresses. Elimination of such impulses would enable a hose to readily stand liquid pressures which are substantially higher (e.g., by at least 20 percent) than maximum permissible pressures for hoses of conventional appaartus. Alternatively, and at unvarying operating pressure, the safety factor of such hoses and other equipment would be improved accordingly.

SUMMARY OF THE INVENTION An object of the invention is to provide a hydraulic pressure amplifying apparatus which can furnish liquid at two or more different elevated pressures without necessitating any interchange, removal or addition of parts.

Another object of the invention is to provide a hydraulic pressure amplifying apparatus which can simultaneously supply liquid at several different elevated pressures without appreciable fluctuations in liquid pressure.

A further object of the invention is to provide a novel hydraulic amplifier for use in an apparatus of the above outlined character.

Still another object of the invention is to provide the hydraulic pressure amplifying apparatus with a novel system of valves which enable the operators to select the desired liquid pressure or pressures in a simple and timesaving manner.

The invention resides in the provision of a hydraulic pressure amplifying apparatus which comprises a highpressure pump having an outlet for discharge of liquid at a first elevated pressure (e.g., at a pressure of up to 200 atmospheres superatmospheric pressure), amplifier means having an outlet for discharge of pressurized liquid at at least one second elevated pressure (if the amplifier means is a two-stage amplifier, it can be designed to amplify the first pressure three or four times so that it discharges pressurized liquid at a pressure of up to 600 or up to 800 atmospheres if the maximum first pressure is 200 atmospheres), conduit means connecting the pump outlet with the amplifier means, and distributor means (preferably comprising a solenoid-operated three-way valve) provided in the conduit means and movable between a plurality of positions in a first of which the distributor means discharges liquid at the first pressure and seals the pump outlet from the amplifier means and in a second of which the distributor means admits at least some liquid from the pump outlet to the amplifier means so that the latter can discharge liquid at a desired second pressure. The distributor means is preferably movable to a third position in which it admits some liquid to the amplifier means and discharges the remaining liquid at first pressure. If the apparatus is used for cleaning of submerged surfaces by jets of pressurized liquid, the distributor means can discharge liquid at first pressure directly to One or more guns which are manipulated by divers to direct jets of liquid against a submerged surface, and the outlet of the amplifier means can supply liquid at an elevated second pressure to one or more additional guns which can direct jets of liquid to the same surface or to a difierent surface.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved hydraulic pressure amplifying apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic plan view of a hydraulic pressure amplifying apparatus which embodies one form of the invention;

FIG. 2 is an enlarged axial sectional view of the amplifier in a first end position of its pistons;

FIG. 3 is a similar axial sectional view of the amplifier with the pistons shown in a second end position; and

FIG. 4 is a graph showing the rate of liquid discharge from the outlet of the amplifier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a hydraulic pressure amplifying apparatus which embodies one form of the invention. The apparatus comprises a hydraulic high-pressure pump 1 of known design which is provided with a pressure regulating valve 9 and has an outlet which delivers liquid at a constant rate. The outlet of the pump 1 can supply pressurized liquid to a pressure amplifier 7 whose outlet 7a is connected with one or more hoses or conduits for discharge of highly pressurized liquid. The hose or hoses and conduits for less pressurized liquid are connected directly to the outlet of the pump 1. The conduit 6 which connects the outlet of the pump 1 with the inlet of the amplifier 7 accommodates a three-way solenoidoperated distributor valve 5. The amplifier 7 is preferably a two-stage device so that the apparatus can furnish liquid at three different pressures, namely, at a lower first pressure directly from the pump 1, at a medium pressure from the amplifier 7 and at a high pressure also from the amplifier.

The operation of the amplifier 7 is based on the differential piston principle. Thus, the effective area of the driving piston multiplied by pressure of liquid which acts against the driving piston equals the area of the driven piston or pistons times liquid pressure. A device for reversing the direction of liquid flow is provided to be actuated in each end position of the driving piston and regulates the operation of a primary regulating valve which in turn controls the operation of a secondary or main regulating valve. In contrast to presently known amplifiers whose transmission ratio is fixed, the amplifier 7 has several stages and is therefore more versatile than conventional amplifiers.

The details of the amplifier 7 are illustrated in FIGS. 2 and 3. This amplifier comprises a housing 01 for a centrally located reciprocable driving piston 02 provided with sealing rings 03, 04. The driving piston 02 is secured to a driven twin piston or plunger 05 whose parts extend in opposite directions and operate in smaller-diameter chambers 06, 07 of the housing 01. The internal surfaces of the chambers 06, 07 have annular grooves for sealing rings 08. Fluid flow reversing members 09, 010 in the form of axially reciprocable rods are in stalled in the housing 01 in the path of movement of the driving piston 02 and are moved axially in response to movement of piston 02 to the respective end positions. These flow reversing rods 09, 010 can pivot two-armed levers 011, 012 which can displace the push rods 013, 014 of a reciprocable valve member 015 in a primary control valve 15. This valve is connected by conduits 13, 14 with a secondary or main control valve 16. The latter comprises a reciprocable valve member 017 having a smaller-diameter portion reciprocable in a first chamber 018 which is normally connected with the outlet of the pump 1 (i.e., with a conduit 11). A second chamber 016 in the main valve 16 can receive pressurized liquid from the valve 15. When the chamber 016 receives liquid, the valve member 017 moves in a direction to the right, as viewed in FIG. 2. The cross-sectional area of the chamber 016 is twice the cross-sectional area of the chamber 018. When the valve 15 permits escape of liquid from the chamber 016, fluid in chamber 018 causes the member 017 to move in a direction to the left. Such movements of the valve member 017 regulate the flow of liquid in conduits 13 and 14.

THE OPERATION The pump 1 is assumed to have an output of 500 liters per minute at a maximum working pressure of 200 atmospheres superatmospheric pressure (determined by the regulating valve 9). The pump 1 is driven by an electric motor 3 by way of a clutch 2. The head 4 of the pump 1 has an outlet connected with the conduit 6 which contains the aforementioned three-way valve 5. The conduit 6 is connected with the pressure amplifier 7 by conduit 11 which contains a shutoif valve 10. When the solenoid of the valve 5 is deenergized, this valve connects the outlet of the pump 1 with a first discharge conduit 8 which discharges water or other liquid at a pressure determined by the regulating valve 9 for the pump 1. Depending on the setting of the valve 9, the conduit 8 will discharge pressurized liquid at a pressure of up to 200 atmospheres superatmospheric pressure. It is now assumed that the setting of the valve 9 insures that the conduit 8 discharges liquid at 200 atmospheres pressure. If the coil of the solenoid in the valve 5 is energized, the latter seals the conduit 8 and admits pressurized liquid into the conduits 11 and 12. Depending on the requirements, the amplifier 7 can amplify the liquid pressure at the ratio of 3:1 or 4:1, i.e., it can discharge liquid at 600 or 0 atmospheres superatmospheric pressure. The consumers are preferably directly connected with the outlet 7a of the amplifier, i.e., without interposition of shutoif valves or the like. This insures that the losses in pressure are mimimal because the resistance to outflow of pressurized liquid is smaller. Furthermore, such connection between the outlet 7a of the amplifier 7 and the consumer or consumers avoids the generation of pressure impulses. The control system for the valve 5 preferably includes an electric circuit including a source of electrical energy (24 volts) adapted to be energized to deenergized from a panel or the like at the working station. It will be noted that the valve 5 is installed at a point where the pressure of liquid is lowest.

It is advisable to provide a separate pressure amplifier for each working station. Each such amplifier can furnish pressurized liquid at a desired pressure or pressures, i.e., each working station can receive liquid at optimum pressure. Such pressure is preferably a multiple of the pressure at the outlet of the pump 1.

For example, if the operator at a Working station requires pressurized liquid at the rate of 50 liters per minute and at a pressure of 800 atmospheres superatmospheric pressure, the pump 1 must deliver 200 liters of liquid at a pressure of 200 atmospheres. Thus, there remain 300 liters at a pressure of 200 atmospheres which can be used to deliver 60 liters per minute at 600 atmospheres to a second consumer. This necessitates the delivery of 180 liters per minute at 200 atmospheres. Thus, the total consumption is 380 liters per minute so that 120 liters per minute at a pressure of 2-00 atmospheres remain for use at a third point (conduit 8).

If the position of the valve 9 is adjusted so that the pump 1 delivers liquid at a pressure of 150 atmospheres, the output requirements are reduced by 25 percent and the pressure at the outlet of the amplifier 7 drops accordingly, namely, to 600 or 450 atmospheres, while the rate of flow remains unchanged.

The improved amplifier can be rapidly converted to amplify the pressure from a ratio of 1:3 to 1:4. This is achieved by the provision of the shutoff valve 10 in the conduit 11. The ratio is 1:4 when the valve 10 is open and 1:3 when the valve 10 is closed, i.e., when the conduit 6 is connected only with the conduit 12.

The conduit 11 comprises branches 11a, 11b which are respectively connected with the smaller-diameter chambers 06, 07 by one-way valves 111a, 1111). One-way valves 211a, 211b discharge pressurized liquid from the chambers 06, 07 to the outlet 7a. The conduit 13 admits or receives liquid from the right-hand larger-diameter chamber 07A by way of the valves 15, 16 and the conduit 14 admits or receives liquid from the left-hand largerdiameter chamber 06A by way of valves 15, 16 (compare FIGS. 2 and 3). The numeral 17 denotes a check valve in the inlet of the pump 1. This valve can connect the conduit 11:: with the inlet of the pump when the valve 10 is closed.

The diagram of FIG. 4 illustrates the rate of liquid discharge from the outlet 7a of the amplifier 7.

The effective area of the surface of the piston 02 is three times the effective area of surface of the piston 05. When the valve 10 is open, the branches 11a, 11b admit liquid to the smaller-diameter chambers 05, 06 and the conduit 12 admits liquid to one of the larger-diameter chambers 06A, 07A whereby the valves 211a, 2111; supply to the outlet 7a liquid at four times the pressure at the outlet of the pump 1 because the effective surface of the piston 02 is added to the effective surface of one half of the piston 05. When the valve 10 is closed to seal the conduits 11a, 11b from the pipe 6, the amplification ratio is three-to-one because the valve 17 then connects the chamber 07 with the inlet of the pump 1 when the chamber 06 is sealed from such inlet by the valve 111a and vice versa. Thus, the valve 211a or 211b will discharge liquid at three times the pressure of fluid admitted by the conduit 12. The valve 111a draws liquid from the inlet of the pump 1 when the valve 211b discharges liquid to a consumer (e.g., to a gun which sprays liquid against a submerged surface) and the valve 111!) draws liquid from the inlet of the pump 1 when the valve 211a discharges liquid at three times the pressure of liquid in the conduit 12.

It will be seen that the improved apparatus can be operated in a number of Ways. When the distributor valve is in a 'first position, the pump 1 delivers to the conduit 8 liquid at a pressure of up to 200 atmospheres (depending on the setting of the regulating valve 9). The valve 5 then seals the outlet of the pump 1 from the conduits 11 and 12. In a second position of the distributor valve 5, the conduit 8 is sealed from the outlet of the pump 1 and all of the liquid discharged by the pump 1 is admitted to the amplifier 7 which can supply pressurized liquid at three or four times the pressure at the outlet of the pump 1. In a third position of the distributor valve 5, some of the pressurized liquid delivered by pump 1 enters the conduit 8 and the remainder of liquid is admitted to the amplifier 7. Thus, the output of the pump 1 can be divided to be supplied to a first consumer by way of the conduit 8 (at a pressure of up to 200 atmospheres) and to a second consumer by way of the outlet 7a (at three or four times the pressure in conduit 8). Three-way valves which can divide the fiow between two conduits are well known in the art. As a rule, such valves are provided with a T-shaped passage for liquid.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art.

What is claimed as new and desired to be protected by Letters Patent is:

1. In a hydraulic pressure amplifying apparatus, a combination comprising pump means having a first outlet means for liquid at a first pressure; two stage amplifier means having a larger diameter driving piston reciprocable between a pair of larger diameter chambers and a pair of smaller diameterpistons reciprocable with and flanking said driving piston and each reciprocable in one of two smaller diameter chambers; conduit means connecting said first outlet means with said amplifier means and including a first conduit having a pair of branch conduits respectively communicating with said two smaller diameter chambers for admitting liquid from said first outlet means into said smaller diameter chambers, and a second conduit, said amplifier means having second outlet means communicating with said smaller diameter chambers; control valve means in said second conduit for admitting liquid at said first pressure to one of said larger diameter chambers 'when said driving piston moves in one direction and to the other larger diameter chamber when said driving piston moves in the opposite direction; and an operator controlled shut-off valve provided in said first conduit and movable to closed position to thereby prevent admission of liquid to said smaller diameter chambers by way of said one conduit whereby said amplifier means delivers to said second outlet means liquid at a lower pressure when said shut-off is closed and at a higher pressure when said shut-off valve is open.

2. A combination as defined in claim 1, wherein said pump means comprises liquid admitting inlet means, and further comprising check valve means connecting one of said branch conduits with said inlet means.

3. A combination as defined in claim 2 and including a one-way valve in each of said branch conduits for permitting flow of liquid through said branch conduit to said smaller diameter chambers while preventing flow of liquid in the reverse direction.

4. A combination as defined in claim 3, wherein said second outlet means is connected with said smaller diameter chambers by 'way of one-way valves permitting flow of liquid from said smaller diameter chambers to said second outlet means by preventing flow of liquid in the reverse direction.

5. A combination as defined in claim 1, and including distributor means in said second conduit means and movable between a plurality of positions, in a first of which said distributor means discharges liquid at said first pressure and in a second of which said distributor means admits at least some liquid from said first outlet means to said amplifier means.

6. A combination as defined in claim 5, wherein said distributor means admits all of the liquid to said amplifier means when in said second position thereof and wherein said distributor means is further movable to a third position in which some of the liquid issuing from said pump means is dscharged from the distributor means at said first pressure and the remainder of liquid issuing from said pump means is admitted to said amplifier means.

7. A combination as defined in claim 5, wherein said distributor means comprises a solenoid-operated threeway valve, said first position of said distributor means corresponding to deenergized condition of said three-Way valve.

References Cited UNITED STATES PATENTS 8/1930 Hatfield et a1. 10351X 8/1948 Rockwell "103-49 

